Difficult Decisions

ALARM Missile
The British government reportedly contemplated giving ALARM missiles to the Ukrainian Air Force. The idea was ultimately dropped over concerns as to whether the missile’s seeker would be effective against Russian radars.

Armada has been told that the United Kingdom Ministry of Defence (MOD) had considered supplying examples of the ALARM missile to Ukraine.

A senior Royal Air Force (RAF) source shared with Armada that consideration had been given to supplying the Ukrainian Air Force (UAF) with British Aerospace/MBDA ALARM (Air-Launched Anti-Radar Missile) examples left over from the type’s decommissioning. Armada understands that plans to supply the missile, and integrate it onto Ukraine’s combat aircraft, stopped amid concerns regarding the missile’s seeker head. It was uncertain if the missile’s Radio Frequency (RF) seeker would have been effective in detecting, and homing in on emissions from Russian radars.

Should it have been deployed, ALARM would have been used to engage Russian ground-based air surveillance and fire control/ground-controlled interception radars.  It was thought that ALARM had been formally retired from RAF service in 2013. The source added that examples of the missile had been retained until 2018. An undisclosed number of missiles were in the possession of the UK Ministry of Defence (MOD) at the time of Russia’s second invasion of Ukraine in February 2022. UAF jets tasked with deploying ALARM would have needed to be upgraded with the necessary software.

Into combat

The Royal Saudi Air Force (RSAF) is believed to be the last ALARM operator and was the missile’s only export customer. Armada has been told in the past that the RSAF deployed ALARM during the country’s intervention in Yemen’s civil war. The RSAF did not specifically deploy ALARM as an anti-radar missile, instead the weapon was used against general surface targets. The source cast doubt on whether the RAF had deployed ALARM during Operation Odyssey Dawn/Unified Protector. This was the codename for the US/North Atlantic Treaty Organisation operation mounted in 2011 to protect Libyan civilians from forces loyal to the country’s late dictator Colonel Muammar Gaddafi.

Tactical modes

ALARM could be deployed in several ways: After launch, the weapon could climb to 40,000 feet (12,192 metres) which gave the missile’s seeker the elevation to detect emissions over a wide area. When used in a direct mode, the missile would look for specific emitters from altitude. Once detected, ALARM would home towards the radar, using the radar signals as guidance. Alternatively, ALARM could be used in a loiter mode. The firing sequence would be similar to direct mode. Once at altitude, the missile would deploy a parachute and slowly descend to Earth while listening for radar emissions. If a hostile radar was detected the parachute would detach, the missile’s motor reignite and it would zoom towards its target. Alternatively, the missile could be programmed to listen out for hostile emissions in a specific area, such as around an airfield. It would be possible for the crew to fire two ALARMs with one set to direct mode and the other to loiter.

Other tactics were available to ALARM users: The missile could be fired on a specific bearing along which it would fly while the seeker would listen out for radar targets of opportunity. This tactic could be particularly effective when there was a need to sanitise an ingress or egress corridor of threats. ALARM could also be programmed before a sortie to strike specific, known targets using latitude and longitude. Coordinates could be changed in the cockpit should a new target emerge during the mission.

Ultimately, the decision not to supply ALARM to the UAF has probably not adversely affected Ukraine’s offensive counter-air and subsequent air defence suppression posture. Given the concerns over the missile’s RF seeker head, it is remains open to question how effective the weapon would have been. To be fair the missile, which was initially selected by the MOD for development in 1983, was built for another age. This late Cold War period was characterised by different radar threats used by Soviet and Warsaw Pact forces. Ironically, the RAF would meet many of these threats in the post-Cold War world in the skies above Iraq and Kuwait in 1991, and later above the Balkans in 1995 and 1999.

By all accounts, ALARM acquitted itself well during these conflicts. Fortunately, the United States has supplied the UAF with Texas Instruments/Raytheon AGM-88B/C High Speed Anti-Radiation Missiles (HARMs). These weapons continue their important work of making life miserable for Russian radar operators in Ukraine.

by Dr. Thomas Withington